still early in my ownership of an E63, so still getting used to it. Today i noticed that the exhaust volume on start up, and for around 10 seconds was nice and loud, and then it dropped by about half. I sounded like a flap or valve was suddenly closing. I have read on here and elsewhere that these cars don't in fact have have any such flaps, and that it is all ECU controlled. So what exactly is happening when the sound lowers, and can it be defeated so it is always what loud? I also read that sport or sport+ makes the exhaust louder than comfort. Is that true, I can't hear any difference?? I really don't want to risk altering the AMG sound so i want to avoid X/H pipe mods.